The bore of a firearm is typically cleaned by using a brush provided on the end of an elongated rod to remove coarse deposits. Brushing is followed by using a cleaning patch, which can be made from a variety of materials such as woven or non-woven fabrics of natural or synthetic fibers, other fibrous materials, or synthetic sheet materials. The patch is typically inserted through a slot formed adjacent the end of an elongated cleaning rod, and soaked in a liquid mixture composed of organic solvents and lubricants. Other cleaning methods utilize special cleaning patch supporting devices. For example, in the universal patch assembly described in United States Patent Publication No. 2013/0269234, published on Oct. 17, 2013, resilient arms maintain the patch in close contact with the bore.
Cleaning a rifle bore, and even the chamber, is a straightforward process. However, the barrel extension or locking lug recess, i.e., the space immediately behind the chamber that receives locking lugs on the end of the bolt, presents problems. Cleaning the barrel extension in a rifle such as the AR10 or AR15 is difficult because the multiple, inwardly protruding, bolt-retention lugs restrict in the opening into which the bolt moves. A similar problem exists in the case of a bolt-action rifle, where the locking lug recess in the action typically has two or three inwardly-protruding lug-retaining walls. In both cases, the inwardly protruding parts make it difficult to introduce a cleaning device that is capable of maintaining pressure against the wall of the barrel extension or the locking lug recess.
One approach to the problem of cleaning barrel extensions has been to use a star-shaped cleaner such as the one depicted in U.S. Design Pat. No. D562,935, granted on Feb. 26, 2008. The cleaner is typically composed of felt, and the points of the star are shaped to pass through the gaps between the bolt-retention teeth of the rifle. However, there remains a need for a cleaning implement that can be utilized with an ordinary cleaning patch, that can enter an internal space through a restricted opening, and that can reliably maintain pressure between the patch and the interior surface of a barrel extension, upper receiver, bolt carrier, locking lug recess, action, or other passage in the firing mechanism of a firearm.